In the typical vapor compression refrigeration system, various components, such as compressor, condenser, evaporator and expansion devices, are arranged to transfer heat energy between a fluid in a heat exchange relationship with an evaporator and fluid in heat exchange relation with the condenser. It is also known in conjunction with such refrigeration systems to utilize a desuperheater for removing superheat energy from gaseous refrigerant prior to circulating said refrigerant to the condenser. One application of such a refrigeration system is a central air conditioning system used in a building. In such application, an enclosure is cooled by circulating, and possibly re-circulating, air from a central air conditioning unit with the enclosure an with ambient air.
In a conventional building installation, a hot water heater is provided to supply heated water to an enclosure. Many such hot water heaters have a cold water inlet connected to an inlet extension pipe and a hot water outlet extending through the top of a hot water tank. Often, an inlet extension pipe is connected to the cold water inlet such that incoming water is directed to the bottom portion of the tank. In hot water tanks, water is heated at the bottom of the tank and rises such that a stratified tank with relatively warm water at the top and cool water at the bottom is provided. When demand is made for hot water, water is discharged from the top of the tank at its warmest temperature and cold water is supplied through the inlet to the bottom portion of the tank.
It is known to combine a refrigeration system and a hot water heating system such that the superheat of the refrigerant may be rejected to Water to be heated such that this heat may be utilized to provide hot water. This heated water may be used for bathing, cleaning, cooking or other uses in a residence. Commercial applications include restaurants, supermarkets, process utilization and any other application wherein waste energy or excess energy from a refrigeration system may be available and hot Water from a tank is also needed.
However, such known systems have several drawbacks that have inhibited their full commercial acceptance. Principal among such drawbacks is the inefficient use made of heat supplied to the hot water heater by the refrigeration system. This inefficient use of heat is coupled with the detriment to the performance of the refrigeration system caused by the hot water heating system. Together, these drawbacks have combined in such a manner such that the increase in hot water heating efficiency has not been sufficient to offset or make up for the reduction in refrigeration efficiency.
Therefore, there is a need for a system which utilizes heat associated with a refrigeration system to heat water in a hot water tank with sufficient efficiency to make such a combination economically feasible an efficient.